Appropriateness Evaluation of Energy Saving Techniques for External Envelope of Residential Buildings Based on Value Engineering Theory

Abstract

Appropriate technology aims to achieve the optimal comprehensive benefits. The improvement of comprehensive benefits depends on the betterment of every benefit and the overall balance between benefits. Through value engineering evaluation, this paper transforms qualitative method into a quantitative method, and uses the new method to compare the comprehensive benefits of technical schemes for energy saving of external envelope of residential buildings, laying the basis for improving technical schemes. Multiple functional indices were determined, and organized into a hierarchical structure. The relative weight of each index was calculated through analytic hierarchy process (AHP). Drawing on the principle of value engineering, function coefficient, cost coefficient, and value coefficient were calculated for examples, and subjected to empirical comparison and analysis. After that, the technical schemes were contrasted, analyzed, and improved, according to the numerical value of the value coefficient. The proposed evaluation system provides a theoretical guide for making investment decisions on energy-saving residential buildings, and avoiding blind investment.

Technical Suitability of Energy Saving Scheme for Optimizing the Thermal Insulation Layer Thickness of Residential Building Exterior Wall

“…The thickness of insulation material determined by calculating the annual operating cost containing annual depreciation and energy loss is called the "economical thickness", and it is the minimum value of annual operating cost. In terms of the economical thickness of exterior wall insulation layer, world field scholars drew on the theory of life cycle evaluation to build economics models of insulation layer thickness for different types of buildings under different climatic conditions, they conducted research from different design angels and proposed methods for determining the economical thickness of insulation layer [14][15][16][17][18][19][20][21][22][23][24][25], and it's found that the regional climate features, building type, operating mode, and the differences in economic and technical levels can all affect the requirements of thermal insulation and energy conservation [26][27][28][29][30][31][32][33][34][35][36][37].…”